Suction apparatuses are known, associated with work machines such as for example laser bridges for an embroidery/sewing machine, like the one described in U.S. Pat. No. 5,915,316, to generate a suction condition in a determinate zone of the machine where during working harmful fumes are produced, generated for example by the laser cut performed before or after the embroidering operation.
Embroidery machines are known for embroidering or applying decorative patterns formed for example by at least a layer of fabric or material on the surface of other fabrics or articles of clothing, shoes or leather-wear.
The known embroidery machine consists of a work bench, one or more embroidery heads attached to the work bench and a cutting unit sliding on a longitudinal guide or laser bridge, to move from an inactive position, in which it does not interfere with the workings of the embroidery head, to an operating position, in which it is disposed in proximity to the embroidery head in order to cut and possibly to remove the superfluous part of the fabric surrounding the part of the fabric embroidered by the embroidery head, and vice versa.
The cutting unit normally comprises at least a laser head that moves along the bridge to position itself in the correct position where it performs the cutting operation. During the cutting operation harmful fumes are generated, which have to be aspirated and expelled to the outside.
It is therefore known to use a suction apparatus that is associated with the laser head and is provided with a suction pipe connected to the cutting unit and mobile therewith to generate the suction of the fumes.
Given that the laser head is mobile along the bridge, the suction pipe is flexible and follows its movements as it moves from the inactive position to the operating position and vice versa, or to an intermediate position.
To this purpose, the suction pipe can be associated with a flexible cable-bearer channel which takes electric feed to the laser head.
The suction pipe, which is normally a pipe made of plastic material associated with a metal coil used for stiffening purposes, unwinds during the movement of the laser head, stretching and retracting depending on the position of the cutting unit.
One disadvantage is that the suction pipe is subjected to a continuous variation in its curvature, in relation to the movement of the laser head. Furthermore, the plastic material gets worn, breakages and cracks form, and therefore it requires frequent maintenance and repair work.
Furthermore, the corrugated surface of the pipe, in conjunction with its curvature, generates large losses of load, which require suction devices with high power.
Moreover, this solution causes a large bulk above the laser head, difficulties in assembly, in transport and in access for the maintenance workers.
A suction apparatus is also known that provides a fixed suction channel, which is associated with and extends for the entire length of the longitudinal guide.
The suction channel is provided with a slit made along its whole longitudinal extension and at the sides of which two bands are associated, disposed with respect to each other so as to form a flap for closing the suction channel.
A divarication element is mounted on the laser head and moves solidly therewith, to selectively act on the closing flap in relation to the position of the laser head. In this way, the suction pipe is selectively connected to the slit through the open segment of the closing flap defined by the strips.
The devarication element is in turn connected to possible pipes to reach the suction zone.
One disadvantage of this solution is the considerable friction that is generated due to the sliding of the surfaces of the divarication element and the two bands, entailing a premature wear of the bands.
Another disadvantage is that, at the extreme sides of the divarication element, the two bands, in correspondence with the point where they divide, determine the formation of gaps, which cause losses of load and reduction in the suction capacity.
Both these known suction apparatuses are complex to make, to assemble, to transport, they are not very flexible or adaptable to the different sizes of the plant and they require frequent maintenance interventions.
One purpose of the present invention is to obtain a suction apparatus for a work machine that is efficient, easy and quick to assemble and transport, and which does not require frequent maintenance interventions over time.
Another purpose of the present invention is to reduce the suction power required.
Another purpose is to obtain an economical suction device that is quickly and easily adapted to the different sizes of the plant.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.